[PATCH 16/16] mm: Account for the number of times direct reclaimers get throttled
From: Mel Gorman <mgorman@suse.de>
Date: 2012-06-22 14:31:14
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - core, memory management - mglru (multi-gen lru), memory management - reclaim, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Johannes Weiner, Linus Torvalds
Under significant pressure when writing back to network-backed storage, direct reclaimers may get throttled. This is expected to be a short-lived event and the processes get woken up again but processes do get stalled. This patch counts how many times such stalling occurs. It's up to the administrator whether to reduce these stalls by increasing min_free_kbytes. Signed-off-by: Mel Gorman <mgorman@suse.de> --- include/linux/vm_event_item.h | 1 + mm/vmscan.c | 3 +++ mm/vmstat.c | 1 + 3 files changed, 5 insertions(+)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 3b54c36..0dee79c 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h@@ -30,6 +30,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, FOR_ALL_ZONES(PGSTEAL_DIRECT), FOR_ALL_ZONES(PGSCAN_KSWAPD), FOR_ALL_ZONES(PGSCAN_DIRECT), + PGSCAN_DIRECT_THROTTLE, #ifdef CONFIG_NUMA PGSCAN_ZONE_RECLAIM_FAILED, #endif
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e25a46f..5a93858 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c@@ -2176,6 +2176,9 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, if (pfmemalloc_watermark_ok(pgdat)) return; + /* Account for the throttling */ + count_vm_event(PGSCAN_DIRECT_THROTTLE); + /* * If the caller cannot enter the filesystem, it's possible that it * is due to the caller holding an FS lock or performing a journal
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 35e0cee..fd345cf 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c@@ -745,6 +745,7 @@ const char * const vmstat_text[] = { TEXTS_FOR_ZONES("pgsteal_direct") TEXTS_FOR_ZONES("pgscan_kswapd") TEXTS_FOR_ZONES("pgscan_direct") + "pgscan_direct_throttle", #ifdef CONFIG_NUMA "zone_reclaim_failed",
--
1.7.9.2
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>